/*
 * Copyright (C) 2007-2010 Geometer Plus <contact@geometerplus.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

package org.geometerplus.fbreader.formats.plucker;

import org.geometerplus.zlibrary.core.filesystem.ZLFile;
import org.geometerplus.zlibrary.core.image.ZLSingleImage;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.zip.DataFormatException;
import java.util.zip.Inflater;

public class ZCompressedFileImage extends ZLSingleImage {
    private final ZLFile myFile;
    private final int myOffset;
    private final int myCompressedSize;

    public ZCompressedFileImage(String mimeType, final ZLFile file, final int offset, final int compressedSize) {
        super(mimeType);
        myFile = file;
        myOffset = offset;
        myCompressedSize = compressedSize;
    }

    public byte[] byteData() {
        try {
            final InputStream stream = myFile.getInputStream();
            if (stream == null) {
                return new byte[0];
            }

            final ArrayList data = new ArrayList();
            byte[] buffer;
            int sizeOfBufferData;

            stream.skip(myOffset);
            byte[] targetBuffer = new byte[myCompressedSize];
            stream.read(targetBuffer, 0, myCompressedSize);
            Inflater decompressor = new Inflater();
            decompressor.setInput(targetBuffer, 0, myCompressedSize);
            do {
                buffer = new byte[4096];
                sizeOfBufferData = decompressor.inflate(buffer);
                data.add(buffer);
            } while (sizeOfBufferData == 4096);
            decompressor.end();
            final int dataSizeMinus1 = data.size() - 1;
            buffer = new byte[dataSizeMinus1 * 4096 + sizeOfBufferData];
            for (int i = 0; i < dataSizeMinus1; ++i) {
                System.arraycopy(data.get(i), 0, buffer, i * 4096, 4096);
            }
            System.arraycopy(data.get(dataSizeMinus1), 0, buffer, dataSizeMinus1 * 4096, sizeOfBufferData);
            return buffer;
        } catch (IOException e) {
        } catch (DataFormatException e) {
        }
        return new byte[0];
    }
}
